Torque motors (gearless direct drive system with high torque) with a hollow shaft are frequently deployed with electric injection molding machines.
With these the motor rotors necessarily have large mass inertia moments. Electric injection molding machines necessarily require a highly dynamic drive system for the technological process as well as a “high-resolution” cycle time for production, in order to be able to manufacture parts cleanly.
In electric injection molding machines at present according to the prior art the required high dynamic is achieved by installing major drive power systems. This means for example at the injection axis that to achieve acceleration times, the installed electric power and/or the available torque is predominantly (>90%) used to accelerate the rotating motor rotor part.